1. Field of the Invention
The present invention relates to buoyancy compensators for scuba divers. More particularly, it relates to a method and apparatus for the construction of a multiple air chamber buoyancy compensator which can be welded together utilizing a single side impregnated fabric.
2. Description of the Prior Art
Buoyancy compensators (BCs) of various designs and construction have been used by scuba divers for many years. The bladder of the BC can be partially filled with air to provide neutral buoyancy to compensate for the weight that the diver is carrying. The bladder can also be inflated by air carried in the diver's tank to raise the diver to the surface in an emergency.
The air chambers in the bladder of modern BCs generally have a bellows construction for compactness when collapsed and have been assembled by gluing layers of fabric together. However, over time the glue deteriorates and the seams come apart. With the development of rubber and particularly urethane coated fabrics, the fabric layers could be radio frequency (RF) or heat welded together at the seams.
The closest known prior art related to the present invention is U.S. Pat. No. 5,385,496, issued Jan. 31, 1995, to Seligman for a Buoyancy Compensator with Lateral Expansion and Method Therefor. It discloses an air chamber construction in FIGS. 1 and 2 thereof which utilizes a single side impregnated fabric, but the design architecture limits the construction to a single air chamber. FIGS. 11-13 thereof disclose multiple chamber designs of fabric construction but the welding architecture requires double side impregnated fabric. It is the multiple chamber design of FIGS. 11-13 which the present invention can accomplish the single side impregnated fabric at great cost savings and longer product life.
The problems with the prior art form of construction for making a bellows type BC include the expense involved in utilizing a fabric which is impregnated on both sides. The fabric is substantially more expensive than a single side impregnated fabric and the fabrics are very expensive and constitute a substantial part of the cost of manufacture. In addition, and equally important, is the fact that an external side impregnated fabric abrades severely in use and in the underwater environment and, when exposed to sunlight, deteriorates and delaminates over time.